C# BindableObject.GetValue方法代码示例

        private static void ItemsSourceChanged(BindableObject bindable, IEnumerable oldValue, IEnumerable newValue) {
            var picker = (Picker)bindable;
            if (picker == null)
                throw new Exception("only support Picker");

            var selected = picker.SelectedIndex;

            var type = newValue.GetType().GenericTypeArguments[0].GetTypeInfo();
            var dp = (string)bindable.GetValue(DisplayPathProperty);
            PropertyInfo p = null;
            if (!string.IsNullOrWhiteSpace(dp)) {
                p = type.GetDeclaredProperty(dp);
            }
            foreach (var o in newValue) {
                object value = null;
                if (p != null)
                    value = p.GetValue(o);
                else
                    value = o;

                if (value != null)
                    picker.Items.Add(value.ToString());
            }

            picker.SelectedIndex = selected;
        }

		internal override void SetUp(BindableObject bindable)
		{
			object newvalue = bindable.GetValue(Property);

			bool newState = (newvalue == Value) || (newvalue != null && newvalue.Equals(Value));
			bindable.SetValue(_stateProperty, newState);
			bindable.PropertyChanged += OnAttachedObjectPropertyChanged;
		}

		void OnConditionChanged(BindableObject bindable, bool oldValue, bool newValue)
		{
			var oldState = (bool)bindable.GetValue(_aggregatedStateProperty);
			var newState = true;
			foreach (Condition condition in Conditions)
			{
				if (!condition.GetState(bindable))
				{
					newState = false;
					break;
				}
			}
			if (newState != oldState)
				bindable.SetValue(_aggregatedStateProperty, newState);
		}

        /// <summary>
        /// Gets the list of pinned elements for the bindable object.
        /// </summary>
        /// <param name="bindableObject">The bindable object to get the list of pinned elements.</param>
        /// <returns>The list of pinned elements of the bindable object.</returns>
        internal static List<VisualElement> GetPinned(BindableObject bindableObject)
        {
            if (bindableObject == null)
            {
                throw new ArgumentNullException(nameof(bindableObject));
            }

            var value = bindableObject.GetValue(PinnedPropertyKey.BindableProperty) as List<VisualElement>;

            if (value == null)
            {
                value = new List<VisualElement>();
                bindableObject.SetValue(PinnedPropertyKey, value);
            }

            return value;
        }

		internal static UITableViewCell GetRealCell(BindableObject cell)
		{
			return (UITableViewCell)cell.GetValue(RealCellProperty);
		}

 public static ImagesCache GetSharedFactory(BindableObject bo)
 {
     return (ImagesCache)bo.GetValue(ImageFactory.SharedFactoryProperty);
 }

 public static double GetFontSize(BindableObject bindable) {
     return (double)bindable.GetValue(FontSizeProperty);
 }

        public static INotifyCollectionChanged GetVMsProperty(BindableObject obj) {
            if (null == (TabbedPage)obj)
                throw new Exception("TabbedPageVMLocatorBinder only used for TabbedPage");

            return (INotifyCollectionChanged)obj.GetValue(VMsProperty);
        }

 public static void SetRenderer(BindableObject bindableObject, IVisualElementRenderer renderer)
 {
     var value = bindableObject.GetValue (RendererProperty);
     bindableObject.SetValue (RendererProperty, renderer);
 }

		internal override bool GetState(BindableObject bindable)
		{
			object newValue = bindable.GetValue(_boundProperty);
			return EqualsToValue(newValue);
		}

 /// <summary>
 /// Gets the AutowireViewModel property value.
 /// </summary>
 /// <param name="bindable"></param>
 /// <returns></returns>
 public static bool? GetAutowireViewModel(BindableObject bindable)
 {
     return (bool?)bindable.GetValue(ViewModelLocator.AutowireViewModelProperty);
 }

        /// <summary>
        /// Gets the position for the object.
        /// </summary>
        /// <param name="bindableObject">The bindable object to get the position for.</param>
        /// <returns>The position that has been assigned to the given object.</returns>
        public static FlyoutPosition GetPosition(BindableObject bindableObject)
        {
            if (bindableObject == null)
            {
                throw new ArgumentNullException(nameof(bindableObject));
            }

            return (FlyoutPosition) bindableObject.GetValue(PositionProperty);
        }

        /// <summary>
        /// Gets the element that the instance is pinned to.
        /// </summary>
        /// <param name="bindableObject">The bindable object to get the pin target for.</param>
        /// <returns>The element that the instance is pinned to.</returns>
        public static VisualElement GetPinTo(BindableObject bindableObject)
        {
            if (bindableObject == null)
            {
                throw new ArgumentNullException(nameof(bindableObject));
            }

            return (VisualElement) bindableObject.GetValue(PinToProperty);
        }

 public static bool GetInAccessibleTree(BindableObject view)
 {
     return (bool)view.GetValue(InAccessibleTreeProperty);
 }

 public static AccessibilityTrait GetAccessibilityTraits(BindableObject view)
 {
     return (AccessibilityTrait)view.GetValue(AccessibilityTraitsProperty);
 }